1. Field of the Invention
The present invention relates to a sports shoe having an insert at least in the heel region of the shoe, the insert including an airtight flexible casing enclosing a series of interconnected elastically deformable bodies.
2. Discussion of the Background
Athletic foot wear is required to provide a stable support region while being simultaneously comfortable for the user. This solves the problem of allowing for comfort while providing stable support and also achieving a counter thrusting effect, i.e., partially recovery of the thrust as the footwear separates from the ground plus absorption of the impact against the ground. In response to this need, solutions of the type described in the following paragraph have been proposed.
Known prior inserts positioned in the footwear heel have acted primarily as a complex spring so that, after the impact of the footwear against the ground and the simultaneous damping effect, there is partial restitution of the energy absorbed by the insert on impact. While all the known inserts offer comfort, stability and adequate damping and energy recovery through a certain range of loading an impact velocity, they can prove partially unsatisfactory outside predetermined parameters. As an example, footwear provided with an insert can satisfy the requirements of slow movement but not of fast movement, whereas an insert designed for fast movement could prove too rigid for slow movement. In addition to this, for equal footwear sizes, the weight of the wearer can vary within extremely wide limits, so that the same insert can prove either rigid or excessively yielding.
Also known are the inserts shown in U.S. Pat. Nos. 5,369,896; 5,092,060 and 5,384,977, the disclosures of which are incorporated herein by reference.